According to Port St. Lucie police Master Sgt. Frank Sabol, the 16-year-old was in the house doing chores. When she went to check on her sister, she found the child face down in the master bathroom bathtub, WPBF reported.

The teen called 911 and performed CPR. The 4-year-old was taken to a hospital, where she was pronounced dead, TCPalm reported.

There were three other children in the house, all boys, ranging in age from 7 to 14, the newspaper reported.

Police detectives are investigating the death as a drowning, Sabol said.

“At this time it just looks like a horrible accident,” Sabol told TCPalm.